JPH0443742B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention comprises a base installed on a surface such as a floor, a rotating body rotatably provided on the base,
an upper arm rotatable around a horizontal axis with respect to a rotating body; a forearm rotatable around a horizontal axis with respect to a distal end of the upper arm; and a wrist assembly attached to the distal end of the forearm. The present invention relates to an improvement in a vertically articulated robot equipped with a motor for rotationally driving an upper arm and a forearm about their rotation axes, and more particularly, to an improvement in the arrangement structure of the upper arm drive motor and the forearm drive motor.

[Conventional technology]

Conventionally, a base installed on a surface such as a floor, a rotating body rotatably provided on the base,
an upper arm rotatable around a horizontal axis with respect to a rotating body; a forearm rotatable around a horizontal axis with respect to a distal end of the upper arm; and a wrist assembly attached to the distal end of the forearm. , a vertically articulated robot equipped with a motor that rotates the upper arm and the forearm about their rotational axes.

In conventional vertically articulated robots, the casing of the drive motor is fixed to the revolving body, and the forearm drive motor is fixed to the upper arm. Further, the upper arm drive motor and the forearm drive motor are disposed coaxially with the rotational axis of the upper arm and protrude from the interconnection portion of the upper arm and the pivoting body on both sides. The output shafts of the upper arm drive motor and the forearm drive motor are respectively connected to the shaft portions of the upper arm and forearm via damping mechanisms or the like.

[Problem that the invention seeks to solve]

In the above-mentioned conventional vertically articulated robot, the moment around the axis of the upper arm increases while the upper arm rotates from a vertical position, that is, a position with the tip of the upper arm pointing directly upwards, to a horizontal position, and the load increases. is added to the upper arm drive motor, so a high output motor is required. Conventionally, a counter balancer mechanism has been incorporated in order to reduce the load applied to the upper arm drive motor, but this has resulted in a complicated structure and increased costs.

On the other hand, the normal working area of a vertically articulated robot is within the range in which the tip of the forearm can swing back and forth 90 degrees to the left and right from the reference position in the direction of rotation of the revolving body. The upper arm drive motor and the forearm drive motor, which protrude from the upper arm and the forearm drive motor, enter the working area of the robot as the rotating body rotates, resulting in a narrowing of the working area of the robot.

[Means for Solving the Problems] In view of the above problems, the present invention has a simple structure that can reduce the load applied to the upper arm drive motor, and
An object of the present invention is to provide a vertically articulated robot that can effectively utilize the working area around the robot.

According to the present invention, the above purpose is to provide a base installed on a surface such as a floor, and a vertical axis (θ axis) on the base.
a rotating body that is provided so as to be able to rotate around the swivel body; an upper arm that is provided that is swivelable around the horizontal axis (W axis) with respect to the swivel body; a forearm rotatably provided, a wrist assembly attached to the distal end of the forearm, and a wrist assembly attached to the distal end of the forearm;
In a vertically articulated robot equipped with a motor that rotates around the upper arm and the forearm (the W axis, the U axis),
In the vertical posture of the upper arm, in which a straight line connecting the robot axis (axis) forms a vertical line, the vertical axis (θ axis) of the rotating body is offset by a predetermined distance D toward the front side of the robot body. At the same time as the upper arm is attached to the rotating body, the housings of both the upper arm and forearm drive motors 24, 25 are moved closer to the straight line connecting the horizontal rotation axis of the upper arm and the horizontal rotation axis of the forearm. disposed on the rear side of the aircraft body and fixed to the upper arms, and the rotation axes of the output shafts of the upper arm drive motor and the forearm drive motor are within a plane orthogonal to the horizontal rotation axis (W axis) of the upper arm. This is achieved by a vertically articulated robot characterized in that the load applied to the upper arm drive motor is compensated for by weight balance, and at the same time, the rotation movement area around the vertical axis is expanded.

[Effect]

According to the vertically articulated robot according to the present invention,
The housings of the upper arm drive motor and the forearm drive motor are arranged behind a line connecting the rotational axis of the upper arm and the rotational axis of the forearm and are respectively fixed to the upper arm,
In addition, since the rotation axes of the upper arm drive motor and the forearm drive motor are arranged in a plane perpendicular to the rotation axis of the upper arm, the weight of the upper arm drive motor and the forearm drive motor reduces the moment generated around the rotation axis of the upper arm. This acts as a counter balancer for the upper arm drive motor, making it possible to reduce the load on the upper arm drive motor. Furthermore, since the rotational axes of the upper arm drive motor and the forearm drive motor are arranged within a plane perpendicular to the rotational axis of the upper arm, these motors do not protrude to the side of the robot. The work space of the robot will not be reduced due to motor restrictions when turning.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

1 to 3 show one embodiment of the present invention. Referring to these figures, the vertically articulated robot has a base 11 installed on a surface such as the floor.
It is equipped with A swing body 12 is supported on the base 11 via a bearing 13 so as to be rotatable around an axis θ perpendicular to the base installation surface. Swivel body 1
A stator housing of a drive motor 14 for the swing body is attached to motor 1.
The output shaft of No. 4 is connected to the base 11 via a reduction gear 15.

A base portion of an upper arm 16 is supported on the swing body 12 so as to be rotatable around a substantially horizontal axis W via a pair of bearings 17 and 18 (see FIG. 2). As can be seen from FIG. 1, here, the rotation axis W of the upper arm 16 is offset forward by a distance D with respect to the rotation axis θ of the swing body 12.

At the tip of the upper arm 16, the rear of the forearm 19 is aligned with the axis W.
It is rotatably supported around an axis U parallel to. A wrist assembly 20 is attached to the distal end of the forearm 19 and is movable around three axes γ, β, and α. The wrist assembly 20 includes three wrist drive motors 2.
1, 22, and 23. Note that, in the present invention, the structure of the wrist assembly 20 itself and its drive mechanism are not important, so detailed illustrations and explanations thereof are omitted.

Inside the upper arm 16, the upper arm 16 is connected to its rotation axis W.
Upper arm drive motor 24 for driving rotation around
and a forearm drive motor 25 for rotationally driving the forearm 19 around its rotational axis U, the stator housings of which are fixed to the upper arm 16.

The housings of the upper arm drive motor 24 and the forearm drive motor 25 are arranged behind a line connecting the rotation axis W of the upper arm 16 and the rotation axis U of the forearm 19, and the housings of the upper arm drive motor 24 and the forearm drive motor 25 The rotational axes of the output shafts 25 are arranged within a plane perpendicular to the rotational axis W of the upper arm 16, respectively.

More specifically, here, the upper arm drive motor 24
whose axis of rotation is the axis of rotation W of the upper arm 16 and the axis of rotation W of the forearm 1
The forearm drive motor 25 is fixed to the upper arm 16 so as to be substantially perpendicular to the line connecting the rotation axis U of the forearm 9 and the rotation axis W of the upper arm 16.
The upper arm 16 is fixed to the upper arm 16 so as to form an acute angle with respect to a line connecting the rotation axis U of the forearm 19.

As schematically shown in FIG. 2, the output shaft of the upper arm drive motor 24 is connected to the swing body 12 via a pair of bevel gears 26, 27 and a speed reducer 28. Further, as schematically shown in FIGS. 1 and 2, the output shaft of the forearm drive motor 25 has a universal joint 29 and a pair of bevel gears 3.
0, 31 and a reduction gear 32 to the forearm 19.

Therefore, the operation of the upper arm drive motor 24 causes the upper arm 16 to rotate around the axis W, and the operation of the forearm drive motor 25 causes the forearm 19 to rotate around the axis U. Normally, the rotating body 12 rotates from the reference position shown in FIG. 1 within a range of approximately 90 degrees left and right, and the upper arm 16 rotates from the vicinity of the vertical position shown in the figure to the angular position of the approximately horizontal position. , the forearm 19 rotates within a range of 90° in both directions from the reference posture perpendicular to the upper arm 16. Therefore, normally, in FIG. 1, the right area of the robot's rotating body 12 becomes the robot's work space.

In the vertically articulated robot having the above configuration, a moment due to the load and self-weight applied to the upper arm 16 is applied around the rotational axis of the upper arm 16, but the upper arm drive motor 24 and the forearm drive motor 2
Since the weight of the upper arm 5 acts as a counter balancer against the moment generated around the rotational axis W of the upper arm 16, the load applied to the upper arm drive motor 24 is reduced.

Further, since the upper arm drive motor 24 and the forearm drive motor 25 extend toward the rear of the robot and do not protrude to the sides of the robot, the working space of the robot is limited to the motor 2 when the rotating body 12 rotates.
4.25 and will not be reduced due to the restrictions of 4.25.

Note that when the upper arm drive motor 24 is placed directly below the rotation axis W of the upper arm 16, the counterbalance effect due to the weight of the motor increases the most, but it becomes necessary to secure installation space for the motor below the axis W. Therefore, a problem arises in that the height of the swing body 12 becomes too high. However, in the vertically articulated robot having the above configuration, the upper arm drive motor 24 extends toward the rear of the robot when the robot is in the standard posture shown in FIG. can.

Although the embodiments shown in the drawings have been described above, the present invention is not limited to the aspects of the embodiments described above. It is also possible to make changes to the power transmission mechanism of the motor.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, the weight of the upper arm drive motor and the forearm drive motor can be effectively used as a counter balancer for the moment generated around the rotational axis of the upper arm, and It is possible to prevent the working space of the robot from being reduced due to restrictions of the motor when turning. Therefore, it is possible to provide a vertically articulated robot in which the upper arm drive motor can be downsized and the working space of the robot can be substantially increased.

[Brief explanation of drawings]

FIG. 1 is a partial cross-sectional, partially transparent side view of a vertically articulated robot schematically showing an embodiment of the present invention, and FIG. 2 is a schematic view of the robot shown in FIG. The sectional view, FIG. 3, is a plan view of the robot shown in FIG. DESCRIPTION OF SYMBOLS 11...Base, 12...Swivel body, 16...Upper arm, 19...Forearm, 20...Wrist assembly, 24...Upper arm drive motor, 25...Forearm drive motor, W...Upper arm rotation axis, U...Forearm rotation axis .

Claims (1)

[Claims] 1. A base 11 installed on a surface such as a floor, a rotating body 12 provided on the base 11 so as to be able to rotate around a vertical axis (θ axis), and the rotating body 12
an upper arm 16 rotatable around a horizontal axis (W axis) relative to the upper arm 16; a forearm 19 rotatable around a horizontal axis (U axis) relative to the distal end of the upper arm 16; a wrist assembly 20 attached to the tip of the upper arm 19, and a motor 2 that rotates the upper arm and forearm about their rotational axes (W, U axes).
4, 25, the horizontal rotation axis (W) of the upper arm 16 and the forearm 19 is
In the vertical posture of the upper arm 16, in which the straight line connecting the U-axis and U-axis forms a vertical line, the straight line is a predetermined distance D toward the front of the robot body from the vertical axis (θ-axis) along which the rotating body 12 rotates. At the same time that the upper arm 16 is attached to the rotating body 12 in an offset manner, the upper arm and forearm drive motor 2
Both housings 4 and 25 are arranged on the rear side of the robot body relative to the straight line connecting the horizontal rotation axis of the upper arm 16 and the horizontal rotation axis of the forearm, and are respectively fixed to the upper arm, and The rotation axes of the output shafts of the drive motor and the forearm drive motor are arranged in a plane perpendicular to the horizontal rotation axis (W axis) of the upper arm, and the load applied to the upper arm drive motor 24 is compensated by weight balance. 2. A vertically articulated robot characterized in that, at the same time, a rotation movement area around the vertical axis is expanded. 2. Claim 1, wherein the upper arm drive motor is fixed to the upper arm so that its rotational axis is approximately perpendicular to a line connecting the rotational axis of the upper arm and the rotational axis of the forearm. The articulated robot described in section.